I’ve had a hamster and cats at the same time. The hamster is so darned dimwitted that it doesn’t recognize the cats as predators who are VERY fond of small rodent snacks. There is a device that is a hollow sphere with holes in it, with a little door. One puts one’s hamster/gerbil/mouse in the sphere, closes the door, and the rodent can run around the house without getting hopelessly lost. When one allows one’s hamster to run about the house in this sphere, the hamster will RUN TO THE CATS, apparently in an effort to make friends with them. This confuses and annoys the cats, who promptly jump out of harm’s way onto a chair, very much like the stereotypical housewife seeing a mouse in the kitchen. We’ve had several hamsters over the years, and they’ve all done this.
Once the hamster is back in its cage, the cats will come out of hiding, and continue to give it the Death Stare.
One of our hamsters was able to escape from his Habitrail, and did so several times. My daughter’s cat caught it and delivered it to my daughter, who did not appreciate having a warm, squirming rodent dumped in her face, no matter how cute he was. Especially since she was asleep at the time. The hamster was unharmed, as was the cat, but I think that my daughter has never fully recovered.